Here are the codecs used:
Sample3 Testfile01: iTunes 7.62 AAC 96kbps VBR
Sample3 Testfile02: Sonicstage 4.3 Atrac3+ 96kbps
Sample3 Testfile03: WMP11 WMA cBR 96kbps
Sample3 Testfile04: Sonicstage 4.3 HE-AAC 96kbps
Many of you guessed HE-AAC correctly.
Thanks to those that voted (those 9 people out of 1700+ views). Discuss the results here.
See you guys in the next poll!